JP2007097040A - Piezoelectric vibrator and piezoelectric oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric oscillator and piezoelectric vibrator capable of dealing with making the piezoelectric oscillator and the piezoelectric vibrator highly functional and making them into compound device. <P>SOLUTION: In a piezoelectric vibrator, within the identical cavity 7 of the same sealed container 1, at least two or more piezoelectric vibrating blanks 11, 12 are housed and on the piezoelectric vibrating blanks 11, 12, exciting electrodes 18, 19 are formed. The piezoelectric vibrators are packaged within the hermetically sealed container 1 so as not to overlap the exciting electrode 18, 19 portions thereof. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a piezoelectric vibrator and a piezoelectric oscillator used in an electronic device such as a portable communication device.

  Conventionally, piezoelectric vibrators and piezoelectric oscillators have been used in electronic devices such as portable communication devices.

  As such a conventional piezoelectric oscillator (here, a piezoelectric oscillator will be described as an example), for example, as shown in FIG. 5, a piezoelectric vibration element plate 111 is mounted on the upper surface of the container 101 and a semiconductor integrated circuit 116 is mounted on the lower surface. . A frame-like side wall 103 is formed on the upper surface of the ceramic substrate laminated on the upper side of the container 101, and a piezoelectric vibration element plate 111 is mounted inside the side wall 103. The piezoelectric vibration element plate 111 is electrically and mechanically held by fixing the piezoelectric vibration element plate 111 to a wiring pattern formed on one end side of the ceramic substrate via a conductive adhesive 113. Further, a lid 104 is joined to the upper surface of the side wall 103 by seam welding or the like, and the piezoelectric vibration element plate 111 is hermetically sealed.

  Further, a component mounting pad (not shown, the same applies hereinafter) is provided on the lower surface of the ceramic substrate laminated on the lower side of the container 101, and the semiconductor integrated circuit 116 for oscillation is mounted on the component mounting pad. .

Further, the side wall portion 105 is electrically and mechanically connected around the lower surface of the ceramic substrate, and four external terminal electrodes 106 are formed at the four corners of the bottom surface of the side wall portion 105. The external terminal electrode 106 is used as, for example, an input / output terminal connected from the piezoelectric vibration element plate 111 via the lead wire 114.
JP 2003-46251 A JP, 2003-101349, A In addition to the prior art literature specified by the above-mentioned prior art literature information, the applicant did not find the prior art literature relevant to the present invention by the time of this application. .

  However, in the conventional piezoelectric oscillator and piezoelectric vibrator described above, it is difficult to make a composite such as arranging a plurality of piezoelectric vibrating base plates in the same sealed container because of its structure. However, it has a drawback that it is difficult to respond to the integration and composite devices.

  The present invention has been conceived in view of the above-described drawbacks. Accordingly, it is an object of the present invention to provide a piezoelectric oscillator and a piezoelectric vibrator capable of increasing the functionality of the piezoelectric oscillator and the piezoelectric vibrator and making it a composite device. is there.

  The piezoelectric vibrator of the present invention is a piezoelectric vibrator in which at least two piezoelectric vibration element plates are accommodated in the same cavity of the same sealed container, and an excitation electrode is formed on the piezoelectric vibration element plate. Each excitation electrode portion of the piezoelectric vibrator is mounted in the sealed container so as not to overlap.

  In addition, the piezoelectric vibrators having the above-described configuration are characterized in that they have a mounting structure in which they are arranged in steps or arranged in parallel at the same height.

  According to another aspect of the present invention, there is provided a piezoelectric oscillator including a semiconductor integrated circuit mounted on the piezoelectric oscillator.

  According to the piezoelectric vibrator of the present invention, there is provided a piezoelectric oscillator in which at least two piezoelectric vibration element plates are housed in the same cavity of the same sealed container, and excitation electrodes are formed on the piezoelectric vibration element plate, Since each excitation electrode portion of each piezoelectric oscillator is mounted in the sealed container so as not to overlap, the frequency adjustment of two piezoelectric vibration element plates can be performed simultaneously in the same process, so that the piezoelectric vibrator is manufactured. The process can be simplified.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol in each figure shall show the same object. FIG. 1 is a sectional view of a piezoelectric oscillator according to an embodiment of the present invention. 1 generally includes a container 1, a side wall 5, a first piezoelectric vibration element plate 11 and a second piezoelectric vibration element plate 12, a semiconductor integrated circuit 16, and a resin 17. Has been. The piezoelectric oscillator shown in FIG. 1 includes a container 1 in which a first piezoelectric vibration element plate 11 and a second piezoelectric vibration element plate 12 are accommodated in a cavity 7, and a side wall 5 is connected to the bottom surface of the container 1. External terminal electrodes 6 are provided at the four corners of the bottom surface of the side wall 5 while being fixed. Further, the semiconductor integrated circuit 16 is mounted on the lower surface of the container 1 located between the side wall portions 5. The semiconductor integrated circuit 16 and the side surface of the side wall 5 are covered with a resin 17.

  FIG. 2 shows one base 2 region cut from a sheet-like mother substrate (not shown). The semiconductor integrated circuit 16 in which the semiconductor integrated circuit 16 and the resin 17 are applied and injected into the sheet-like mother substrate. It is a bottom view of the circuit 16 mounting surface side.

  The container 1 includes, for example, a base 2 made of a ceramic material such as glass-ceramic and alumina ceramic, a side wall 3 made of a ceramic material similar to the base 2, and a lid 4 made of alloy, copal, phosphor bronze, etc. The side wall 3 is attached to the upper surface of the base 2, and the lid 4 is placed and fixed on the upper surface of the base 2. Thus, the container 1 is formed, and the conductive adhesive 13 is attached to the upper surface of the base 2 located inside the side wall 3. The first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12 are mounted via The container 1 has a first piezoelectric vibrating element plate 11 and a second piezoelectric element in a cavity 7 surrounded by the inside thereof, specifically, the upper surface of the base 2, the inner surface of the side wall 3, and the lower surface of the lid body 4. This is for accommodating the vibration element plate 12 and hermetically sealing it.

  On the other hand, the first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12 housed in the cavity 7 of the container 1 have a pair of excitation electrodes on both main surfaces of a piezoelectric piece cut along a predetermined crystal axis. When the fluctuating voltage from the outside is applied to the piezoelectric piece through the pair of excitation electrodes 18 and 19, thickness-shear vibration is caused at a predetermined frequency.

  On the other hand, as shown in FIGS. 1 and 2, side walls 5 are attached and formed on the lower surface of the base 2 described above, and external terminal electrodes formed at the four corners of the bottom surface of the side walls 5. A flip-chip type semiconductor integrated circuit 16 formed in a rectangular shape is mounted on the lower surface of the base 2 positioned between the semiconductors 6. The semiconductor integrated circuit 16 is connected to the base 2 via a conductive adhesive 15. ing. In addition, the semiconductor integrated circuit 16 and the side wall 5 are covered with a resin 17.

  The semiconductor integrated circuit 16 has temperature compensation data for compensating temperature characteristics of the temperature sensing element, the first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12 on the circuit forming surface. A temperature compensation circuit for correcting the excitation characteristics of the first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12 according to a temperature change based on temperature compensation data; An oscillation circuit or the like for generating the oscillation output is provided, and the oscillation output generated by the oscillation circuit is output to the outside and then used as a reference signal such as a clock signal. Here, the first piezoelectric vibration element plate 11, the second piezoelectric vibration element plate 12, and the semiconductor integrated circuit 16 are connected by a lead wire 14 provided in the inner layer of the base 2 shown in FIG.

  3 and 4 are cross-sectional views when the embodiment of the present invention is applied to a piezoelectric vibrator. In FIG. 3, the container 1 is provided with a step so that the first piezoelectric vibrating element plate 11 and the second piezoelectric vibrating plate 11 FIG. 4 shows an example in which the piezoelectric vibration element plates 12 are arranged in different stages. FIG. 4 shows an example in which the first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12 are arranged in parallel in the container 1 at the same height. This is an arrangement structure of piezoelectric vibrators.

  Next, the manufacturing method of the piezoelectric oscillator mentioned above is demonstrated using FIG. 1, FIG. 2 which is embodiment of this invention. First, a sheet-like mother substrate (not shown) having a plurality of cavities 7 arranged in a matrix of m columns × n rows (m and n are natural numbers of 2 or more) is prepared. Next, as shown in FIG. 1, the side walls 3 surrounding the first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12 are mounted in each cavity 7. Each cavity 7 is provided with a pair of connection pads and a bonding conductor layer on the upper surface thereof. Further, the side wall portion 5 is mounted around the base 2 on the side where the semiconductor integrated circuit 16 is mounted on the surface opposite to the cavities 7. Further, external terminal electrodes 6 are formed on the bottom surface of the side wall portion 5 as shown in FIG.

  The base 2 made of such a sheet-like mother board is formed by connecting, for example, connecting pads or the like on the surface of a ceramic green sheet obtained by adding an appropriate organic solvent to a ceramic material powder made of alumina ceramics and mixing them. A conductor paste to be used as the external terminal electrode 6 or the like is printed in a predetermined pattern and applied, and a plurality of the pastes are laminated and press-molded, and then fired at a high temperature.

  The sheet-like mother board is generally provided with a predetermined separation area (not shown) between the individual piezoelectric oscillators arranged in a matrix. Two temperature compensation control terminals (not shown) are connected to each piezoelectric oscillator in this surplus area. Then, one each of the first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12 are mounted inside the side wall 3 formed on the sheet-like mother substrate having the cavity 7. The first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12 are electrically and mechanically connected to the excitation electrodes 18 and 19 and the corresponding mounting pads on the upper surface of the sheet-like mother substrate through the conductive adhesive 13. Are connected to each other and mounted on a sheet-like mother board.

  In addition, the metal lid body 4 having a plurality of cover (lid) areas corresponding to the cavities 7 of the sheet-like mother board on a one-to-one basis is used as the first piezoelectric vibration element plate 11 and the second piezoelectric vibration. It mounts and joins on the side wall 3 so that the base plate 12 may be sealed. As the lid 4, for example, a metal plate having a thickness of 60 μm to 100 μm made of a metal such as 42 alloy, Kovar, phosphor bronze or the like is used. Similar to the substrate, a predetermined margin area is provided between the cover areas.

  In this step, the cover 4 is formed in a sheet shape so that the first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12 are arranged in the cavity 7 region corresponding to the inside of each cover (lid) region. Then, the lid 4 is attached to the upper surface of the side wall 3 and fixed by bonding them together by means of conventionally known gold tin sealing or the like. The series of joining steps described above is preferably performed in an inert gas atmosphere such as nitrogen gas or argon gas, whereby the first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12 are accommodated. Since the inert gas is filled in the space, the first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12 are effectively prevented from being corroded and deteriorated by oxygen or moisture in the atmosphere. be able to.

  Next, the semiconductor integrated circuits 16 are mounted one by one in the region surrounded by the side wall 5 on the lower surface of the sheet-like mother board. The semiconductor integrated circuit 16 is mounted on the sheet-like mother board by electrically and mechanically connecting the connection electrodes and corresponding mounting pads on the lower surface of the sheet-like mother board via the conductive adhesive 15. . Thereafter, resin 17 is applied and injected so that the entire side surface of the side wall 5 is covered.

  Then, the semiconductor integrated circuit 16 has temperature compensation data for compensating the temperature characteristics of the temperature sensing element detecting the ambient temperature state on the circuit forming surface and the temperature characteristics of the first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12. To the semiconductor integrated circuit 16 having a temperature compensation circuit for correcting the excitation characteristics of the first piezoelectric vibration element plate 12 and the second piezoelectric vibration element plate 12 according to the temperature change based on the temperature compensation data. Bit data is input from the temperature compensation control terminal and the temperature compensation data is written so that the specification of the oscillator becomes a desired value.

  Finally, the sheet-like mother board is collectively divided and cut (diced) along the outer periphery of each base 2 region, whereby a plurality of piezoelectric oscillators are simultaneously manufactured. Further, the cutting (dicing) of the sheet-like mother substrate is performed by collectively cutting (dicing) these members using a dicer or the like, and thereby a plurality of piezoelectric oscillators can be obtained simultaneously. .

  Here, as shown in FIG. 1, the characteristic part of the present invention is that the excitation electrodes 18 and 19 of the first and second piezoelectric vibrating base plates 11 and 12 do not overlap in the same sealed container 1. This is because it is fixed and stored in such a positional relationship. As a result, the frequency adjustment of the first and second piezoelectric vibrating base plates 11 and 12 can be performed simultaneously in the same process, so that the manufacturing process of the piezoelectric oscillator can be simplified.

  Further, according to the piezoelectric oscillator of the present invention, when the first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12 are operated at the same frequency, the first piezoelectric vibration element plate 11 is always oscillated. The second piezoelectric vibration element 12 is subjected to setting processing in the semiconductor integrated circuit 16 so as to operate by detecting abnormal oscillation of the first piezoelectric vibration element 11, so that the second piezoelectric vibration element 12 can be used for applications requiring high reliability. Can be used.

  Further, according to the piezoelectric oscillator of the present invention, one of the first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12 operates as a function of an oscillator by the semiconductor integrated circuit 16, and the remaining one piezoelectric vibration element. Since the element plate operates as a function of the vibration element plate alone without using the semiconductor integrated circuit 16, the first piezoelectric element member 11 that functions as a piezoelectric oscillator that compensates the temperature by the semiconductor integrated circuit 16 and the vibration element member alone. Since the second piezoelectric vibrating element 12 that functions as a piezoelectric oscillator that oscillates the oscillation frequency can be accommodated in the same sealed container 1, the piezoelectric oscillator can be combined.

  In addition, this invention is not limited to the above-mentioned embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.

  For example, in the above-described embodiment, only the first piezoelectric vibration element plate 11 and the second piezoelectric vibration element plate 12 are accommodated in the same sealed container 1, but the third and fourth piezoelectric vibration element plates are further provided. May be accommodated. In the above-described embodiment, only one semiconductor integrated circuit 16 is mounted. However, the semiconductor integrated circuits 16 may be mounted as many as the number of piezoelectric vibration element plates accommodated in the same sealed container 1. . Needless to say, this case is also included in the technical scope of the present invention.

1 is a schematic cross-sectional view of a piezoelectric oscillator according to an embodiment of the present invention. 1 is a bottom view of a semiconductor integrated circuit mounting surface side showing a state in which a semiconductor integrated circuit and resin of a piezoelectric oscillator according to an embodiment of the present invention are applied and injected. FIG. FIG. 5 is a cross-sectional view of the case where the embodiment of the present invention is developed in a piezoelectric vibrator, in which a step is provided in the container and the first piezoelectric vibration element plate and the second piezoelectric vibration element plate are arranged in a stepwise manner. . It is a case where the embodiment of the present invention is developed in a piezoelectric vibrator, and is a cross-sectional view when a first piezoelectric vibration element plate and a second piezoelectric vibration element plate are arranged in parallel at the same height in a container. It is a schematic perspective view of a conventional piezoelectric oscillator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Container 2 ... Base 3 ... Side wall 4 ... Cover body 5 ... Side wall part 6 ... External terminal electrode 7 ... Cavity 11 ... 1st piezoelectric vibration element Plate 12 ... Second piezoelectric vibrating base plate 13 ... Conductive adhesive 14 ... Extract wiring 15 ... Conductive adhesive 16 ... Semiconductor integrated circuit 17 ... Resin 18 ... Excitation electrode of first piezoelectric vibration element plate 19... Excitation electrode of second piezoelectric vibration element plate

Claims (3)

A piezoelectric vibrator in which at least two piezoelectric vibration element plates are housed in the same cavity of the same sealed container, and an excitation electrode is formed on the piezoelectric vibration element plate,
A piezoelectric vibrator characterized in that each excitation electrode portion of each piezoelectric vibrator is mounted in the hermetically sealed container so as not to overlap. The piezoelectric vibrator according to claim 1, wherein the piezoelectric vibrator has a mounting structure in which the piezoelectric vibrators are arranged in steps or arranged in parallel at the same height. A piezoelectric oscillator comprising the piezoelectric vibrator according to claim 1 or 2 and a semiconductor integrated circuit.

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